This is great until
I think that's the point. Don't jump to the complex right away. Keep it simple and compose the capabilities you have readily available until you need to become more complex. When the task requires it, yeah, do the complex thing, but keep the simplicity mandate in mind and only add the new complexity that you need. You can get pretty far with the simple, and what about all of the situations where that future pivot or growth never happens?
The philosophy strikes a cord with me - I'm often contending with teams that are building for the future complexities that they think might come up, and we realize later that we did get complexity in the problem later, but not the kind we had planned for, so all of that infrastructure and planning was wasted on an imaginary problem that no only didn't help us but often actually make our task harder. The trick is to keep the solution set composable and flexible so that if complexity shows up later, we can reconfigure and build the new capabilities that we need rather than having to maneuver a large complicated system that we built on a white board before we really knew what the problem looked like.
I absolutely agree, but you're talking about a situation where we already have 10 different ways and 20 EC2 instances. When you get to that point (or start approaching it), yeah, do the complex thing - no argument at all. The challenge is to wait until the last responsible moment to make that pivot and to not dive deeper into the complexity than you need at the current time and place. I've worked with countless small companies and teams in the past that have created whole K8s clusters, Terraform provisioning plans, and the whole kit for a single low volume service because "we'll need it when things scale out later" and later never arrives.